Washington will join a group of other states challenging proposed new rules by the Trump administration that state Attorney General Bob Ferguson described Monday as part of “scorched earth immigration policies.”

The 19 states and the District of Columbia will be trying to block a change the administration proposed last week as a way to deal with minors who enter the country at the southern border seeking asylum, sometimes with adult family members and sometimes as unaccompanied minors.

The proposed change would allow families to be detained for long periods of time in facilities selected by the federal government that are not licensed or inspected by the state, Ferguson said. Currently, children who are separated after arriving with adult family members or are unaccompanied minors can be sent to stay in Washington, but only at state-licensed facilities.

As part of the lawsuit, the state is filing a 26-page affidavit detailing reports of crowded, unsanitary and inhumane conditions at detention centers near the southern border, which investigators heard about from young immigrants who were later relocated to licensed facilities in Washington.

“The impacts of this administration’s scorched-earth immigration policies are devastating and long-lasting to these kids,” Ferguson said at a news conference where he was flanked by Democratic legislators, representatives of the legal assistance group Kids In Need of Defense and members of his office who handle civil rights cases.

He described the separation of children from parents and their incarceration as a “shameful chapter” in American history, likening it to the internment of Japanese Americans during World War II.

“Someday my kids – all of our kids – will look back and say ‘What on God’s green earth were you thinking?’ ” he said.

An agreement in a 1997 federal case, known as the Flores settlement, sets guidelines for separating children from adults who are placed in detention centers while awaiting a decision on their immigration status. One of the guidelines requires facilities for children to be state-licensed, and states don’t license detention centers.

With the crush of asylum-seekers from Central America on the southern border, existing facilities have been overwhelmed. The administration has been criticized for keeping children in temporary facilities longer than the settlement allows and in overcrowded facilities that far exceed their capacity.

In announcing the proposed rules, which would take effect in 60 days, Acting Homeland Security Secretary Kevin McAleenan said the goal is to keep families together and create higher standards for family detention centers, the Associated Press reported. They would use standards for education, food and cleanliness used by Immigration and Customs Enforcement, rather than state licensing requirements.

Homeland Security officials said last week the new facilities will be audited, and the audits made public.

But Ferguson said the rule change was an attempt “to take away state oversight.”

The federal government currently has 100 beds in Washington that it can use for children after they are moved out of detention centers. In the last year, 566 were placed in Washington facilities for various lengths of time.

The lawsuit, filed in Sacramento, is asking for a preliminary injunction against the rule change until the court can review the arguments for and against the federal government’s proposal. It is the 47th lawsuit Washington has led or joined against the Trump administration.